--[[ Element: Auras

 Handles creation and updating of aura icons.

 Widget

 Auras   - A Frame to hold icons representing both buffs and debuffs.
 Buffs   - A Frame to hold icons representing buffs.
 Debuffs - A Frame to hold icons representing debuffs.

 Options

 .disableCooldown    - Disables the cooldown spiral. Defaults to false.
 .size               - Aura icon size. Defaults to 16.
 .onlyShowPlayer     - Only show auras created by player/vehicle.
 .showStealableBuffs - Display the stealable texture on buffs that can be
                       stolen.
 .spacing            - Spacing between each icon. Defaults to 0.
 .['spacing-x']      - Horizontal spacing between each icon. Takes priority over
                       `spacing`.
 .['spacing-y']      - Vertical spacing between each icon. Takes priority over
                       `spacing`.
 .['growth-x']       - Horizontal growth direction. Defaults to RIGHT.
 .['growth-y']       - Vertical growth direction. Defaults to UP.
 .initialAnchor      - Anchor point for the icons. Defaults to BOTTOMLEFT.
 .filter             - Custom filter list for auras to display. Defaults to
                       HELPFUL on buffs and HARMFUL on debuffs.

 Options Auras

 .numBuffs     - The maximum number of buffs to display. Defaults to 32.
 .numDebuffs   - The maximum number of debuffs to display. Defaults to 40.
 .gap          - Controls the creation of an invisible icon between buffs and
                 debuffs. Defaults to false.
 .buffFilter   - Custom filter list for buffs to display. Takes priority over
                 `filter`.
 .debuffFilter - Custom filter list for debuffs to display. Takes priority over
                 `filter`.

 Options Buffs

 .num - Number of buffs to display. Defaults to 32.

 Options Debuffs

 .num - Number of debuffs to display. Defaults to 40.

 Examples

   -- Position and size
   local Buffs = CreateFrame("Frame", nil, self)
   Buffs:SetPoint("RIGHT", self, "LEFT")
   Buffs:SetSize(16 * 2, 16 * 16)
   
   -- Register with oUF
   self.Buffs = Buffs

 Hooks and Callbacks

]]

local parent, ns = ...
local oUF = ns.oUF

local VISIBLE = 1
local HIDDEN = 0

local UpdateTooltip = function(self)
	GameTooltip:SetUnitAura(self:GetParent().__owner.unit, self:GetID(), self.filter)
end

local OnEnter = function(self)
	if(not self:IsVisible()) then return end

	GameTooltip:SetOwner(self, "ANCHOR_BOTTOMRIGHT")
	self:UpdateTooltip()
end

local OnLeave = function()
	GameTooltip:Hide()
end

local createAuraIcon = function(icons, index)
	icons.createdIcons = icons.createdIcons + 1

	local button = CreateFrame("Button", nil, icons)
	button:RegisterForClicks'RightButtonUp'

	local cd = CreateFrame("Cooldown", nil, button, "CooldownFrameTemplate")
	cd:SetAllPoints(button)
	cd:SetDrawEdge(false)

	local icon = button:CreateTexture(nil, "BORDER")
	icon:SetAllPoints(button)

	local count = button:CreateFontString(nil, "OVERLAY")
	count:SetFontObject(NumberFontNormal)
	count:SetPoint("BOTTOMRIGHT", button, "BOTTOMRIGHT", -1, 0)

	local overlay = button:CreateTexture(nil, "OVERLAY")
	overlay:SetTexture"Interface\\Buttons\\UI-Debuff-Overlays"
	overlay:SetAllPoints(button)
	overlay:SetTexCoord(.296875, .5703125, 0, .515625)
	button.overlay = overlay

	local stealable = button:CreateTexture(nil, 'OVERLAY')
	stealable:SetTexture[[Interface\TargetingFrame\UI-TargetingFrame-Stealable]]
	stealable:SetPoint('TOPLEFT', -3, 3)
	stealable:SetPoint('BOTTOMRIGHT', 3, -3)
	stealable:SetBlendMode'ADD'
	button.stealable = stealable

	button.UpdateTooltip = UpdateTooltip
	button:SetScript("OnEnter", OnEnter)
	button:SetScript("OnLeave", OnLeave)

	table.insert(icons, button)

	button.icon = icon
	button.count = count
	button.cd = cd

	--[[ :PostCreateIcon(button)

	 Callback which is called after a new aura icon button has been created.

	 Arguments

	 button - The newly created aura icon button.
	 ]]
	if(icons.PostCreateIcon) then icons:PostCreateIcon(button) end

	return button
end

local customFilter = function(icons, unit, icon, name, rank, texture, count, dtype, duration, timeLeft, caster)
	if((icons.onlyShowPlayer and icon.isPlayer) or (not icons.onlyShowPlayer and name)) then
		return true
	end
end

local updateIcon = function(unit, icons, index, offset, filter, isDebuff, visible)
	local name, rank, texture, count, dtype, duration, timeLeft, caster, isStealable, shouldConsolidate, spellID, canApplyAura, isBossDebuff = UnitAura(unit, index, filter)
	if(name) then
		local n = visible + offset + 1
		local icon = icons[n]
		if(not icon) then
			--[[ :CreateIcon(index)

			 A function which creates the aura icon for a given index.

			 Arguments

			 index - The offset the icon should be created at.

			 Returns

			 A button used to represent aura icons.
			]]
			icon = (icons.CreateIcon or createAuraIcon) (icons, n)
		end

		local isPlayer
		if(caster == 'player' or caster == 'vehicle') then
			isPlayer = true
		end

		icon.owner = caster
		icon.filter = filter
		icon.isDebuff = isDebuff
		icon.isPlayer = isPlayer


		--[[ :CustomFilter(unit, icon, ...)

		 Defines a custom filter which controls if the aura icon should be shown
		 or not.

		 Arguments

		 self - The widget that holds the aura icon.
		 unit - The unit that has the aura.
		 icon - The button displaying the aura.
		 ...  - The return values from
		 [UnitAura](http://wowprogramming.com/docs/api/UnitAura).

		 Returns

		 A boolean value telling the aura element if it should be show the icon
		 or not.
		]]
		local show = (icons.CustomFilter or customFilter) (icons, unit, icon, name, rank, texture, count, dtype, duration, timeLeft, caster, isStealable, shouldConsolidate, spellID, canApplyAura, isBossDebuff)
		if(show) then
			-- We might want to consider delaying the creation of an actual cooldown
			-- object to this point, but I think that will just make things needlessly
			-- complicated.
			local cd = icon.cd
			if(cd and not icons.disableCooldown) then
				if(duration and duration > 0) then
					cd:SetCooldown(timeLeft - duration, duration)
					cd:Show()
				else
					cd:Hide()
				end
			end

			if((isDebuff and icons.showDebuffType) or (not isDebuff and icons.showBuffType) or icons.showType) then
				local color = DebuffTypeColor[dtype] or DebuffTypeColor.none

				icon.overlay:SetVertexColor(color.r, color.g, color.b)
				icon.overlay:Show()
			else
				icon.overlay:Hide()
			end

			local stealable = not isDebuff and isStealable
			if(stealable and icons.showStealableBuffs and not UnitIsUnit('player', unit)) then
				icon.stealable:Show()
			else
				icon.stealable:Hide()
			end

			icon.icon:SetTexture(texture)
			icon.count:SetText((count > 1 and count))

			local size = icons.size or 16
			icon:SetSize(size, size)

			icon:EnableMouse(true)
			icon:SetID(index)
			icon:Show()

			--[[ :PostUpdateIcon(unit, icon, index, offest)

			 Callback which is called after the aura icon was updated.

			 Arguments

			 self   - The widget that holds the aura icon.
			 unit   - The unit that has the aura.
			 icon   - The button that was updated.
			 index  - The index of the aura.
			 offset - The offset the button was created at.
			 ]]
			if(icons.PostUpdateIcon) then
				icons:PostUpdateIcon(unit, icon, index, n)
			end

			return VISIBLE
		else
			return HIDDEN
		end
	end
end

--[[ :SetPosition(from, to)

 Function used to (re-)anchor aura icons. This function is only called when
 new aura icons have been created or if :PreSetPosition is defined.

 Arguments

 self - The widget that holds the aura icons.
 from - The aura icon before the new aura icon.
 to   - The current number of created icons.
]]
local SetPosition = function(icons, from, to)
	local sizex = (icons.size or 16) + (icons['spacing-x'] or icons.spacing or 0)
	local sizey = (icons.size or 16) + (icons['spacing-y'] or icons.spacing or 0)
	local anchor = icons.initialAnchor or "BOTTOMLEFT"
	local growthx = (icons["growth-x"] == "LEFT" and -1) or 1
	local growthy = (icons["growth-y"] == "DOWN" and -1) or 1
	local cols = math.floor(icons:GetWidth() / sizex + .5)

	for i = from, to do
		local button = icons[i]

		-- Bail out if the to range is out of scope.
		if(not button) then break end
		local col = (i - 1) % cols
		local row = math.floor((i - 1) / cols)

		button:ClearAllPoints()
		button:SetPoint(anchor, icons, anchor, col * sizex * growthx, row * sizey * growthy)
	end
end

local filterIcons = function(unit, icons, filter, limit, isDebuff, offset, dontHide)
	if(not offset) then offset = 0 end
	local index = 1
	local visible = 0
	local hidden = 0
	while(visible < limit) do
		local result = updateIcon(unit, icons, index, offset, filter, isDebuff, visible)
		if(not result) then
			break
		elseif(result == VISIBLE) then
			visible = visible + 1
		elseif(result == HIDDEN) then
			hidden = hidden + 1
		end

		index = index + 1
	end

	if(not dontHide) then
		for i = visible + offset + 1, #icons do
			icons[i]:Hide()
		end
	end

	return visible, hidden
end

local UpdateAuras = function(self, event, unit)
	if(self.unit ~= unit) then return end

	local auras = self.Auras
	if(auras) then
		if(auras.PreUpdate) then auras:PreUpdate(unit) end

		local numBuffs = auras.numBuffs or 32
		local numDebuffs = auras.numDebuffs or 40
		local max = numBuffs + numDebuffs

		local visibleBuffs, hiddenBuffs = filterIcons(unit, auras, auras.buffFilter or auras.filter or 'HELPFUL', numBuffs, nil, 0, true)
		auras.visibleBuffs = visibleBuffs

		local hasGap
		if(visibleBuffs ~= 0 and auras.gap) then
			hasGap = true
			visibleBuffs = visibleBuffs + 1

			local icon = auras[visibleBuffs] or (auras.CreateIcon or createAuraIcon) (auras, visibleBuffs)

			-- Prevent the icon from displaying anything.
			if(icon.cd) then icon.cd:Hide() end
			icon:EnableMouse(false)
			icon.icon:SetTexture()
			icon.overlay:Hide()
			icon.stealable:Hide()
			icon.count:SetText()
			icon:Show()

			--[[ :PostUpdateGapIcon(unit, icon, visibleBuffs)

			 Callback which is called after an invisible aura icon has been
			 created. This is only used by Auras when the `gap` option is enabled.

			 Arguments

			 self         - The widget that holds the aura icon.
			 unit         - The unit that has the aura icon.
			 icon         - The invisible aura icon / gap.
			 visibleBuffs - The number of currently visible buffs.
			]]
			if(auras.PostUpdateGapIcon) then
				auras:PostUpdateGapIcon(unit, icon, visibleBuffs)
			end
		end

		local visibleDebuffs, hiddenDebuffs = filterIcons(unit, auras, auras.debuffFilter or auras.filter or 'HARMFUL', numDebuffs, true, visibleBuffs)
		auras.visibleDebuffs = visibleDebuffs

		if(hasGap and visibleDebuffs == 0) then
			auras[visibleBuffs]:Hide()
			visibleBuffs = visibleBuffs - 1
		end

		auras.visibleAuras = auras.visibleBuffs + auras.visibleDebuffs

		local fromRange, toRange
		if(auras.PreSetPosition) then
			fromRange, toRange = auras:PreSetPosition(max)
		end

		if(fromRange or auras.createdIcons > auras.anchoredIcons) then
			(auras.SetPosition or SetPosition) (auras, fromRange or auras.anchoredIcons + 1, toRange or auras.createdIcons)
			auras.anchoredIcons = auras.createdIcons
		end

		if(auras.PostUpdate) then auras:PostUpdate(unit) end
	end

	local buffs = self.Buffs
	if(buffs) then
		if(buffs.PreUpdate) then buffs:PreUpdate(unit) end

		local numBuffs = buffs.num or 32
		local visibleBuffs, hiddenBuffs = filterIcons(unit, buffs, buffs.filter or 'HELPFUL', numBuffs)
		buffs.visibleBuffs = visibleBuffs

		local fromRange, toRange
		if(buffs.PreSetPosition) then
			fromRange, toRange = buffs:PreSetPosition(numBuffs)
		end

		if(fromRange or buffs.createdIcons > buffs.anchoredIcons) then
			(buffs.SetPosition or SetPosition) (buffs, fromRange or buffs.anchoredIcons + 1, toRange or buffs.createdIcons)
			buffs.anchoredIcons = buffs.createdIcons
		end

		if(buffs.PostUpdate) then buffs:PostUpdate(unit) end
	end

	local debuffs = self.Debuffs
	if(debuffs) then
		if(debuffs.PreUpdate) then debuffs:PreUpdate(unit) end

		local numDebuffs = debuffs.num or 40
		local visibleDebuffs, hiddenDebuffs = filterIcons(unit, debuffs, debuffs.filter or 'HARMFUL', numDebuffs, true)
		debuffs.visibleDebuffs = visibleDebuffs

		local fromRange, toRange
		if(debuffs.PreSetPosition) then
			fromRange, toRange = debuffs:PreSetPosition(numDebuffs)
		end

		if(fromRange or debuffs.createdIcons > debuffs.anchoredIcons) then
			(debuffs.SetPosition or SetPosition) (debuffs, fromRange or debuffs.anchoredIcons + 1, toRange or debuffs.createdIcons)
			debuffs.anchoredIcons = debuffs.createdIcons
		end

		if(debuffs.PostUpdate) then debuffs:PostUpdate(unit) end
	end
end

local Update = function(self, event, unit)
	if(self.unit ~= unit) then return end

	UpdateAuras(self, event, unit)

	-- Assume no event means someone wants to re-anchor things. This is usually
	-- done by UpdateAllElements and :ForceUpdate.
	if(event == 'ForceUpdate' or not event) then
		local buffs = self.Buffs
		if(buffs) then
			(buffs.SetPosition or SetPosition) (buffs, 0, buffs.createdIcons)
		end

		local debuffs = self.Debuffs
		if(debuffs) then
			(debuffs.SetPosition or SetPosition) (debuffs, 0, debuffs.createdIcons)
		end

		local auras = self.Auras
		if(auras) then
			(auras.SetPosition or SetPosition) (auras, 0, auras.createdIcons)
		end
	end
end

local ForceUpdate = function(element)
	return UpdateAuras(element.__owner, 'ForceUpdate', element.__owner.unit)
end

local Enable = function(self)
	if(self.Buffs or self.Debuffs or self.Auras) then
		self:RegisterEvent("UNIT_AURA", UpdateAuras)

		local buffs = self.Buffs
		if(buffs) then
			buffs.__owner = self
			buffs.ForceUpdate = ForceUpdate

			buffs.createdIcons = 0
			buffs.anchoredIcons = 0
		end

		local debuffs = self.Debuffs
		if(debuffs) then
			debuffs.__owner = self
			debuffs.ForceUpdate = ForceUpdate

			debuffs.createdIcons = 0
			debuffs.anchoredIcons = 0
		end

		local auras = self.Auras
		if(auras) then
			auras.__owner = self
			auras.ForceUpdate = ForceUpdate

			auras.createdIcons = 0
			auras.anchoredIcons = 0
		end

		return true
	end
end

local Disable = function(self)
	if(self.Buffs or self.Debuffs or self.Auras) then
		self:UnregisterEvent("UNIT_AURA", UpdateAuras)
	end
end

oUF:AddElement('Aura', Update, Enable, Disable)
